A silver halide color photographic material generally comprises a support having coated thereon light-sensitive layers composed of three kinds of silver halide emulsion layers each selectively sensitized to have light sensitivity to blue light, green light, or red light in a multilayer structure and each silver halide emulsion layer containing a photographic coupler forming a yellow, magenta, or cyan dye. A color image can be obtained by subjecting the color photographic material to color development processing with a color developer after image-exposure.
As a result of the color development, an aromatic primary amine color developing agent undergoes an oxidation coupling reaction with the photographic couplers, which results in forming azomethine series or indophenol series colored dyes. It is important that the colored dyes are clear yellow, magenta, and cyan dyes each having a less side absorption for obtaining a color photographic image showing a good color reproducibility.
Other important properties required for photographic couplers are sufficient color density, high color sensitivity, good graininess (fine dye cloud), etc.
In the case of a silver halide color photographic material for in-camera use, the graininess of the color images and the sensitivity are particularly important. That is, the graininess is important so that photographic images do not roughen when the photographic images is enlarged and sensitivity is important for designing a high-sensitive photographic light-sensitive material which can be used for photography even in a dark place. These properties also greatly influence the kind of silver halide emulsion being used and the design of a color photographic material also becomes easy by using couplers having excellent properties in these points.
Recently, two kinds of pyrazolotriazoles have been developed as magenta couplers providing azomethine dyes having less side absorption and the practical use of these couplers for color photographic materials have been proceeded.
One kind is the 1H-pyrazolo 1,5-b! 1,2,4!triazole magenta coupler described in JP-B-2-44051 (the term "JP-B" as used herein means an "examined published Japanese patent application"), U.S. Pat. No. 4,540,654, etc., and another kind is the 1H-pyrazolo 5,1-c! 1,2,4!triazole (or also called a 1H-pyrazolo 3,2-c! 1,2,4!triazole) magenta coupler described in JP-B-47-27411, U.S. Pat. No. 3,725,067, etc. These magenta couplers have been used for color photographic papers and color photographic negative films and have greatly contributed to the improvement of the color reproducibility and the storage stability.
Furthermore, the imidapyrazoles described in U.S. Pat. No. 4,500,630, the pyrazolotetrazoles described in JP-A-60-33552 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), the pyrazolobenzimidazoles described in West German Patent 1,070,030, the pyrazoloazoles described in JP-A-60-43,659, and the indazolinones described in West German Patent 814,996 are disclosed as couplers for improving the color reproducibility although they have not yet been practically used.
To improve the graininess of a color photographic material, as the couplers for fining the dye cloud, four equivalent (theoretically, 4 mols of silver halide are required for forming 1 mol of a dye) or more equivalent couplers are preferable. Thus, for using the pyrazolotriazole couplers, etc., described above for this purpose, an increase in the equivalency of these couplers is required but simple four equivalent couplers (i.e., the releasing group is a hydrogen atom) of these couplers have insufficient stability and hence a new approach has been desired.
As a technique for solving this problem, there are the blocked couplers disclosed in JP-A-56-133734 and JP-A-60-191253. The coupler is, for example, a coupler formed by introducing a pyrazolotriazole coupler having a ballast group into the releasing group portion of a yellow coupler forming a water-soluble azomethine dye and is so designed that after coloring the yellow coupler, the pyrazolotriazole coupler, which becomes colorable upon release, colors and remains in the film, while the yellow dye flows out in the developer, whereby the coupler can become an apparent four to six equivalent coupler.
However, the couplers described in the above-described patent publications have problems in that the flowout of the water-soluble dye formed after development processing is insufficient (inferior decoloring), the improvement in the graininess and the sensitivity is insufficient, and further the synthesis of these couplers is difficult. Thus it has been desired to solve the problems.
Also, there is a method of adding hydroquinones or gallic acids each having a non-diffusible group but in this case, in particular, in a color reversal photographic light-sensitive material, there is the problem that in the first development (black and white development), the compound accelerates silver development resulting in a deterioration in graininess.